Cavity systems with pressure bubbles or chambers that can be adjusted to a desired pressure corresponding to the comfort of the user by being filled or emptied are used to adjust the lumbar support in vehicle seats. This comfort setting can be provided with a so-called memory function which shall be able to reproduce the preset fill level of the cavity system even when the cavity system has been temporarily emptied, as for example when switching off the vehicle or using the reclining adjustment for storing purposes or the like. To this end, the fill level is stored in a memory. For example, the ability to measure the fill pressure of a cavity system using a pressure sensor is known from JP 2008 007 017. The pressure value is saved and when refilling can be recalled through a reading of the pressure sensor returning said pressure the previously set value.
It is the objective of the present invention is to specify an aforementioned method and vehicle seat system that can realize a memory function and that can do completely without the use of pressure sensors.